We do both domestic and international, and it usually works fine because we avoid doing peak season or peak travel days. For some reason we never have much trouble getting there, but occassionaly my SO has to buy a return ticket. She's pretty busy so it's worth it for her not to spend an unplanned extra day non-reving.
If you plan your travels based on realistic loads and leave yourself an extra day to return, you should be fine.
I have always worked at regionals that had multiple major codeshares, which provided extra non-rev flexibility, ie you could just list when necessary without having to get a stack of ZED/ID90 in advance.